Coco peat (cocopeat), also known as coir pith. coir fibre pith, coir dust, or simply coir, is made from coconuthusks, which are byproducts of other industries that use coconuts. Coir waste from coir fiber industries is washed, heat-treated, screened and graded before being processed into coco peat products of various granularity and denseness, which are then used for horticultural and agricultural applications and as industrial absorbent.

Usually shipped in the form of compressed bales, briquettes, slabs or discs, the end user usually expands and aerates the compressed coco peat by the addition of water. A single kilogram of coco peat will expand to 15 litres of moist coco peat.

Trichoderma is a naturally occurring fungus in coco peat; it works in symbiosis with plant roots to protect them from pathogenic fungi such as pythium. It is not present in sterilized coco peat. Trichoderma is also destroyed by hydrogen peroxide.

Coco peat is used as a soil additive. Due to low levels of nutrients in its composition, coco peat is usually not the sole component in the medium used to grow plants. When plants are grown exclusively in coco peat, it is important to add nutrients according to the specific plants' needs. Coco peat from Philippines,Sri Lanka and India contains several macro- and micro-plant nutrients, including substantial quantities of potassium. This extra potassium can interfere with magnesium availability. Adding extra Magnesium through the addition of Epsom salts can correct this issue.

Some Coco peat is not fully decomposed when it arrives and will use up available nitrogen as it does so (known as drawdown), competing with the plant if there is not enough. Poorly sourced coco peat can have excess salts in it and needs washing (check electrical conductivity of run-off water, flush if high). It has a similar cation exchange capacity to sphagnum peat, holds water well, re-wets well from dry and holds around 1000 times more air than soil. Adding slow release fertilizers or organic fertilizers are highly advised when growing with coco peat.

Common uses of coco peat include:

As a substitute for peat, because it is free of bacteria and most fungal spores, and is sustainably produced without the environmental damage caused by peat mining.

Mixed with sand, compost and fertilizer to make good quality potting soil. Coco peat generally has an acidity in the range of pH - 5.5 to 6.5. It is a little on the acidic side for some plants, but many popular plants can tolerate this pH range.

Being a good absorbent, dry coco peat can be used as an oil absorbent on slippery floors. Coco peat is also used as a bedding in animal farms and pet houses to absorb animal waste so the farm is kept clean and dry. Coco peat is hydrophilic unlike sphagnum moss and can quickly reabsorb water even when completely dry. Coco peat is porous and cannot be overwatered easily.

Coco peat can harbour organisms that pose a threat to the biosecurity of countries into which it is imported. Coco peat has been imported into New Zealand since about 1989 with a marked increase since 2004. By 2009 a total of 25 new weed species have been found in imported coco peat. The regulations relating to importing coco peat into New Zealand have been amended to improve the biosecurity measures.[1]